The subject matter of the present disclosure broadly relates to the art of suspension systems including gas spring assemblies and, more particularly, to a suspension system that include logic control circuit adapted to utilize a sensor signal from a height sensor to selectively operate a valve arrangement to increase and/or decrease the height of the gas spring assembly. A height control system that includes the logic circuit as well as a suspension system and method are also described.
It will be appreciated that the subject gas spring assembly, height control system, suspension system and method are amenable to broad use in a wide variety of applications and environments. One example of a suitable application includes use of the foregoing in connection with an associated vehicle, and the subject matter of the present disclosure will be discussed in detail hereinafter with specific reference to use in operative association with an associated vehicle. However, it is to be specifically understood that the subject gas spring assembly, height control system, suspension system and method are capable of broad application and are not intended to be limited to this specific example of a suitable application.
Gas spring assemblies of a variety of type and kinds are known to be used in suspension systems between opposing structural components of a vehicle. Additionally, a variety of devices and/or arrangements have been and are currently used to effect control of the relative position of one structural component of the vehicle to another structural component. As one example, a mechanical linkage valve that is in fluid communication between a compressed gas source and a gas spring assembly can be interconnected between the opposing structural components. As the structural components move toward and away from one another, the valve opens and closes to permit pressurized gas to be transferred into and out of the gas spring assembly. In this manner, such mechanical linkage valves can permit control of the height of the gas spring assembly.
Unfortunately, such arrangements have a number of problems and/or disadvantages that are commonly associated with the continued use of the same. One problem with the use of mechanical linkage valves, particularly those used in association with the suspension system of a vehicle is that the linkages are frequently subjected to physical impacts, such as may be caused by debris from a roadway, for example. This can result in the linkage being significantly damaged or broken, such that the valve no longer operates properly, if the valve operates at all.
Due to the potential for known mechanical linkage valves to be damaged, regular inspection and replacement of such mechanical linkage valves is typically recommended. In geographical areas where road conditions may be poor and result in the increased potential for damage, such as developing countries, for example, the capability to inspect and repair such components will often be limited or may even be unavailable. As such, a gas spring assembly that avoids the use of mechanical linkages is desirable.
Another disadvantage of known mechanical linkage valves relates to the performance and operation thereof in connection with an associated suspension system. That is, known mechanical linkage valves generally open and close under predetermined height conditions regardless of the operating condition or inputs acting on the vehicle. As such, it is possible that operating conditions of the vehicle might occur during which the performance of a height change would be undesirable. Unfortunately, conventional suspension systems that utilize mechanical linkage valves are not typically capable of selective operation.
Height control systems for vehicle suspension systems have been developed that avoid the use of mechanical linkage valves. Additionally, such systems are often capable of selective operation such that height changes can be avoided under certain conditions of operation of the vehicle. In most cases, however, it seems that such known height control systems are highly sophisticated and rely upon complex algorithms and software that operates within electronic controllers having relatively high-speed processors to perform the height control computations. In addition to the high relative cost of known height control systems, the capability to maintain and repair such systems may be limited, or even unavailable. This provides further disincentive for the adoption and use of gas spring assemblies for vehicle suspension systems.
As such, it is believed to be beneficial to develop a suspension system including gas spring assemblies and a height control circuit for overcoming the foregoing and/or other deficiencies that may exist in the art. In addition, the subject matter of the present disclosure also includes an air suspension system including a variable hysteresis circuit to control the response of the air suspension system, i.e. to tighten or loosen the suspension response.